Electric welding machine



March 7, 1944'. F. MARTlNDELL 2,343,637

I ELEGTRIC WELDING MACHINE Original Filed Sept. 4, 1942 4 Sheets-Sheet 1 A 770mm March 7 1944.

F. MARTINDELL ELECTRIC WELDING MACHINE Original Filed Sept 4, 1942 4 Sheets-Sheet 2 A TTORA/F Y March 7, 1944' F. MARIINDELL ELECTRZ'I WELDING MACHINE Original Filed Sept. 4, 1942 4 Sheets-Sheet 3 J.L I T v KMART/A/DELL v March 7, 1944. F. MARTINDELL ELECTRI C WELDING MACHINE Original Filed Sept. 4, 1942 4 Sheets-Sheet 4 FIG/0 m/ vmrbk EMA RTl/VDH L Patente d Mar. 7,1944

Frank Martindell,

Western Springs, 111., aasig'nor to Western Electric Company,

Incorporated,

New York, N. Y., a corporation New York Original application Se 6 Claims. (G

This invention relates to electric welding machines, and more particularly to machines for welding contacts to switch springs or other elements of electrical apparatus, and is a division of the co-pending application of Frank Martindell, Serial No. 457,243, filed September 4, 1942.

Objects of the invention are to provide an improved and highly efficient electric welding machine of the type referred to.

In accordance with one embodiment of the invention, an electric contact welding machine is provided which comprises a pair of opposed welding electrodes mounted for oscillatory movement toward and away from each other by being supported on the free ends of a series of metal reeds or flat springs which also serve to conduct the welding current to the welding electrodes. The machine further comprises means for intermittently advancing two strips of contact metal to insert the end portions thereof between the two electrodes, means for locating and supporting a switch spring or the like between the end portions of the contact metal strips, means for moving the two electrodes toward each other to clamp the end portions of the contact metal strips to opposite sides of the switch spring, and means for severing the clamped end portions from the continuous strips prior to the welding operation.

Other features and advantages of the invention will be apparent from the following detailed description when read in conjunction with the accompanying drawings, in which:

Fig. i is a plan view of a contact welding machine embodying the features of the invention;

Fig. 2" is a front elevational view thereof Fig. 3 is an enlarged fragmentary vertical sectional view taken on line 3-3 of Fig. 1;

Fig. 4 is an enlarged fragmentary vertical sectional view taken on'line t--|i of Fig. 1;

Fig. 5 is an enlarged fragmentary horizontal sectional view taken. on line 5-5 of Fig. 2;

Figs. 6, '7 and 8 are enlarged detail sectional views taken on lines 5-, 'i-'l, and 8--8, respectively, of Fig. 5: and

Figs. 9 and 10 are plan and elevation views, respectively, of a switch spring having contacts welded to opposite sides thereof by means of the welding machine of Figs. 1 to 8, inclusive.

The. machine illustrated in the drawings is capable of welding simultaneously to opposite sides of a switch spring is (Figs. 9 and 10), two bar type contacts it, it previously severed by the machine from two continuous strips 28, 20 of contact metal drawn from a supply roll 28 (Fig.

ptember 4, 1942, Serial No. 457,243. Divided and this application January 9, 1943, Serial No. 471,825

1). The machine comprises two circular welding electrodes 22, 22 which are mounted for movement toward and away from each other in the manner hereinafter described. The switch spring is placed on a shelf-like supporting bracket I! which is provided with a plurality of pins or projections) i9, i9 for locating and holding the switch spring in an edgewise position with an end portion thereof disposed between the two welding electrodes, as best shown in Figs. 3, 4 and 5.

' Each of the welding electrodes is clamped to a circular head portion 24 of a horizontal electrode supporting her 25 which is secured to the free upper ends of a series of vertically disposed metal reeds or flat springs 26,, 28 (Fig. 4). At their lower ends, these flat springs are anchored to L-shaped metal blocks 21, 21 fixed to a base plate 28. Thus, due to the flexibility of the electrode supporting springs 26, the two welding electrodes are capable of oscillatory movement toward and away from each other. Moreover, since the electrode supporting springs are flexible in one plane only, they permit movement of the welding electrodes in one plane only and thus serve to guide the electrodes in their movements toward and away from each other so that the guideways usually provided for this purpose may be eliminated. The electrode supporting springs also serve to conduct the welding current from the fixed blocks 21 to the movable welding elec trodes. By means of suitable bus bars 29, portions of which are shown in Figs. 2 and 4, the welding current is conducted to the blocks 27 from a suitable current supply source (not shown).

It will be obvious that the spring mounting blocks 27 may be positioned on the base plate so that the springs will be tensioned so as to urge I the two electrodes either toward each other or away from each other. However, in the illustrated embodiment of the invention, separate means are provided for moving the electrodes toward and away from each other. Thus, for moving the electrodes toward each other, there is associated with each of the electrode supporting bars 25 a spring pressed plunger 30 which. bears against a depending lug 3| on the tail end Each of the of the electrode supporting bar. plungers is housed in a casing 32 which is adjustably mounted, as shown in Fig. 4, in the upper end of a vertical supporting plate 33 securedto the base plate.

The welding electrodes are moved away from each other and are held in their retracted positions, shown in the drawings, by means of two electrical solenoids, 35, 35, one for each electrode.

Each of these solenoids is operatively connected to the associated electrode supporting bar through a bell crank 36 rotatably mounted on a vertical supporting post 31 (Figs. 2 and 4). Each of the bell cranks comprises a long horizontal arm 33 and a short vertical arm 39. The horizontal arm is pivotalb' connected by means of a link 40' to the plunger H of the associated solenoid 35, and the vertical arm carries a roller 43 which bears against a depending lug H on the forward end of the electrode supporting bar. The vertical arms of the two bell cranks are interconnected by a coil spring 45 which serves to counter-balance the weight of the bell cranks so that this weight is not required to be overcome by the electrode operating plungers 30. Thus, upon deenergization of the solenoids 35, the welding electrodes are quickly moved toward each other under the forces of the spring pressed plungers 30, which forces may be adjusted by simply adjusting the positions of the plunger casings 32 in the supporting plate 33.

Each of the electrode supporting bars 25 is formed with a longitudinal bore 41 (Fig. for

slidably accommodating a knife carrying bar 38, the forward end of which is offset so that a shoulder 49 is provided for engaging the forward end of the electrode supporting bar to limit outward movement of the knife carrying bar. A chisel-like knife 50 is secured to the offset forward end of each knife supporting bar, and it will be noted by referring to Fig. 5 that the knives 50 slidably engage the fiat back surfaces of the welding electrodes 22. An adjustable gib 52 is provided in the bore H of each of the electrode supporting bars for holding the knife in close sliding engagement with the back surface of the electrode. Each ,of the knives is held in its retracted position by a coil spring 53 which is compressed between a shoulder 54 on associated knife carrying bar 48 and a shoulder 55 in the bore 41 of associated electrode supporting bar 25.

The outer end of each knife carrying bar 48 extends beyond the outer end of the associated electrode supporting bar 25 and is adapted to be engaged by a roller 51 (Fig. 4) on a vertical rocker arm 53 secured to a horizontal shaft 60 rotatably journaled in supporting plate 33. A stop pin 6i on plate 33 limits clockwise movement of this rocker arm and a spring .63 holds the rocker arm against the stop pin. A horizontal arm 64 is secured at one end to the shaft 60 and is provided at its outer end with an ad- .Iustable abutment screw '65 which is adapted to be struck by a plunger 51 of an electrical sole hold 58, whereby the shaft 60 is rocked counterclockwise thereby causing rocker arm 53 to operate the knife bar 48. An adjustable stg) pin 59 on plate 33 is adapted to be engaged by arm II to limit the counter-clockwise movement of the rock shaft 60.

The contact strip feeding mechanism com-. prises a tubular spindle (Figs. 3 and 5), which is endwise slidable in a sleeve or tubular casing 16. the latter being slidable in a guide block 71 secured to a vertical supporting plate I3. At the forward end of the spindle I5 there is attached a chuck 80 comprising a rigid tongue-like center .jaw 8i (Fig. 5) and two pivoted jaws 82. 82 on opposite sides of the rigid jaw. The two contact strips pass through the spindle andemerge therefrom on opposite sides of the rigid chuck jaw 3|, and each of the pivoted jaws is adapted to cooperate with the rigid jaw to grip one of the contact strips. The pivoted Jaws are formed with tapered outer surfaces 33, 33 and the forward end of casing I8 is formed with an internal tapered surface 84 for cooperating with the tapered surfaces 83 of the pivoted jaws to close them when the chuck together with the spindle is shifted toward the right (Fig. 3) relative to the casing.

The spindle and chuck are normally urged toward the right (Fig. 3) by a coil spring 35 which serves to yieldably hold the chuck laws in their clamping positions. This spring encircles the spindle and is compressed between the chuck and a spacer bushing 81 disposed in the tail end portion of casing '16. Endwise movement of the spindle toward the left against the opposing force of spring 86 is accomplished by an electrical solenoid 90. A plunger SI of this solenoid is connected by a link 92 to a horizontal arm 33 of a bell crank 94 which is pivoted at 35 on supporting plate I8. A bifurcated vertical arm 95 of this bell crank is adapted to engage a flanged collar 38 on the tail end of the spindle to shift the latter toward the left when the bell crank is rocked counter-clockwise by solenoid 33. An adjustable stop screw I00 limits counterclockwise movement of the bell crank 94 and clockwise movement thereof is limited by a similar adjustable stop screw IOI. A coil spring I03 yieldably holds the bell crank against stop screw iii.

The casing '16 is yieldably urged toward the right (Fig. 3) by an adjustable coil spring I05 and an external shoulder I08 on the casing cooperates with an internal shoulder I01 in guide block 17 to limit the extent of endwise movement of the casing under the force of the spring. An external shoulder I09 on the tail end of the casing is adapted to be engaged by a bifurcated end of a vertical rocker arm III) which is secured to a horizontal shaft H2 rotatably journaled in supporting plate 18. Also secured to shaft 2 is a horizontal arm III which is connected by a link H5 to a plunger II6 of an electrical solenoid II1. Thus, when this solenoid is energized. the shaft together with rocker arm 96 is rotated in a counter-clockwise direction, thereby re tractin the casing I6 toward the left (Fig. 3). An adjustable stop screw II9 limits the extent of counter-clockwise movement of the bell crank. whereby the retraction of the casing 15 i also limited.

In the operation of the machine, the solenoids 35 normally hold the two welding electrodes 22 in their retracted positions against the opposing force of the spring pressed plungers 30, and solenoid I I1 normally holds the contact strip feeding mechanism in its retracted position against the opposing force of spring I05. The chuck carrying spindle 15 is held in its retracted position by solenoid which is opposed by the spring 86. Upon deenergization of this solenoid. the spindle is moved toward the right (Fig. 3) by spring 86, whereby the chuck jaws are caused to firmly grip the two contact metal strips in the manner described above. Then solenoid III is deenergized, whereupon the spring I05 moves the entire contact strip feeding mechanism toward the right to the position shown in Fig. 3. thus inserting the end portions of the two contact strips 20 between the two electrodes and on opposite sides of a switch spring I5 placed by the operator on the support I 8. Solenoids 35 are then de-energized, whereupon the spring pressed plungers 30 move the two welding electrodes toward each other thus clamping the end portions of the two contact metal strips to opposite sides of the switch spring. Next, solenoid 90 is energized and thereby caused to retract the chuck carrying spindle, thus releasing the chuck jaws.

- contact strips to opposite sides of the switch spring, solenoids '68 are momentarily energized and thereby caused to operate the knives 50 to sever the clamped end portions from the continuous contact metal strips, after which .the knives are retracted by the springs 53 (Fig. 5). The severed end portions of the contact metal strips are then electrically welded to opposite sides of the switch spring, the welding current being conducted to the electrodes by the flexible electrode supporting reeds 26. After the welding operation,-so1enoids 35 are energized and thereby caused to retract the welding electrodes, thus completing an operating cycle of the machine.

It is to be understood that the invention is i not limited to the embodiments thereof herein illustrated and described but is capable of other applications within the scope of the appended claims.

What is claimed is:

1. In a contact welding machine, a pair of welding electrodes mounted for oscillatory movement toward and .away from each other, means for positioning and supporting a switch spring between the two electrodes, means for advancing simultaneously and in spaced parallel relationship two continuous strips of contact metal to present the end portions thereof to opposite sides of the switch spring, and means for moving the electrodes toward each other to clamp the end portions of the contact metal strips to opposite sides of the switch spring. 1

2. In a contact welding machine, a pair of welding electrodes mounted for movement toward and away from each other, means for positioning and supporting a switch spring between the two electrodes, and means for feeding the end portions of two continuous strips of contact metal to opposite sides of the switch spring, said feeding means comprising a reciprocatory chuck having two pivoted jaw members and an intermediate rigid jaw member for cooperating with the pivoted jaw members to advance the two strips of contact metal in spaced parallel relationship.

3. In a contact welding machine, a pair of welding electrodes mounted for oscillatory movement toward and away from each other, means for positioning and supporting a switch spring between the two electrodes, means for feeding the end portions of two continuous strips of contact metalto opposite sides of the switch spring, means for moving the electrodes toward each other to clamp the end portions of the contact metal strips to opposite sides of the switch spring, and means for severing the clamped end portions from the continuous strips.

4. In a contact welding machine, a pair of welding electrodes mounted for oscillatory movement toward and away from each other, a pair of reciprocatory knives, one for each electrode,

means for positioning and'supporting a switch spring between the two -electrodes, means for feeding-the end portions of two continuous strips of contact metal to opposite sides of the switch spring, means for moving the electrodes toward each other to clamp the end portions of the contact metal strips'to opposite sides of the switch spring, and means for operating .the knives to sever the clamped end portions from the continuous strips.

5. In a contact welding machine, a pair of welding electrodes mounted for oscillatory movement toward and away from each other, means for positioning and supporting a switch spring between the two electrodes, means for feeding the end portions of two continuous strips of contact metal to opposite sides of the switch spring, means for moving the electrodes toward each other to clamp the end portions of the contact metal strips to opposite sides of the switch spring, a pair of reciprocatory knives, one for each electrode, for severing the clamped end portions from the continuous strips, and electromagnetically actuated means for operating said knives.

6. In a contact welding machine, a pair of welding electrodes mounted for movement toward and away from each other, means for positioning and supporting a switch spring between the two electrodes, electromagnetically actuated means for feeding the end portions of two continuous strips of contact metal to opposite sides of the switch spring, electrcmagnetically actuated means for moving the electrodes toward each other. to clamp the end portions of the contact metal strips to opposite sides of the switch spring, and electromagnetically actuated knives for severing the clamped end portions from the continuous strips.

FRANK MARI'INDEIL 

